FIOS firewall with NIS firwall

I'm connecting to the Internet using Verizon FIOS (fiber optic).   I have a single computer at home not othewise connected in a LAN,  just a simple connection to the Internet.    The FIOS router sitting on my desk has it's own firewall and is active.  I'm also using NIS 2010 and I have the NIS  firewall active (Window 7 Home Premium 64 bit is my OS).   I'm having no problems with both firewalls in use.  Is there any reason I should "turn off" either the NIS firewall or the firewall provided by the router?    I have had no conflicts, to date.   Thanks for info.